GLOSSARY

Caloric Surplus means that intake exceeds expenditure over the interval considered, increasing stored body energy overall. The resulting gain is not necessarily all muscle, and scale weight can include changing water.

Over a defined interval, a difference between metabolizable energy intake and energy expenditure changes stored body energy. This principle does not imply that daily scale weight directly reveals energy balance. Water, glycogen and gut contents also contribute to body mass. Intake and expenditure influence each other through behavior and physiology, so projecting the same daily deficit indefinitely creates unrealistic predictions. Interpret the energy equation together with its timescale and the composition of the tissues changing.

Total expenditure includes energy needed at rest, the thermic effect of food and physical activity. Planned exercise is only part of activity expenditure. Work, walking and spontaneous movement can also matter. When an estimate already includes a component, adding it again double counts energy. Establish whether an exercise value is gross or net of resting expenditure, and use the same convention when comparing days or combining wearable estimates with a daily energy model.

Energy expenditure can change during weight loss because a smaller body costs less to maintain and move, and because additional adaptive responses may occur. These explanations should be distinguished rather than calling every reduction a damaged metabolism. Appetite and spontaneous movement can also change. The size and persistence of adaptation vary. Reassess trends and recovery under comparable conditions instead of assuming that an equation's initial prediction remains the correct maintenance intake throughout a changing training and weight-loss period.